Flange-lock slider

ABSTRACT

A ladder-type filamentary slide fastener has a flange-lock slider in which a single locking projection extends into the slider channel from only one of the two flanges on each side thereof whereby the slider exhibits improved locking characteristics, increased smoothness in slider operation and reduced fastener binding and wear.

ljite States Patent Mueller Mar. 26, 1974 FLANGE-LOCK SLIDER 3,449,8036/1969 Manning 244205.14 R

Z 2 2 5. 75 Inventor: Gilbert A. Mueller, St. Catharines, 6 788 H1966Sambe'g 4/ Q R Ontario, Canada P E. B d A. l k [73] Assignee:Textr0n,lnc., Providence, RI. "man mmmer emar Gea [22] Filed: May 18,1972 57 ABSTRACT [21] Appl No.: 254,360 1 A ladder-type filamentaryslide fastener has a flange- U S 24/205 14 lock slider in which a singlelocking projection extends [51] 'A 19):) into the slider channel fromonly one of the two [58] i 74/305 14 flanges on each side thereofwhereby the slider exhib- 7 h its improved locking characteristics,increased [56] References Cited smoothness in slider operation andreduced fastener binding and wear. UNITED STATES PATENTS 1,890,33612/1932 Nodine v. 24/205.15 R 1 Claim, 3 Drawing Figures FLANGE-LOCKSLIDEIR BACKGROUND OF THE INVENTION 1. Field of the Invention Thepresent invention relates to slide fasteners and, more particularly, toan improved flange-lock slider for a ladder-type filamentary fastener.

2. Description of the Prior Art In many applications for filamentaryslide fasteners, such as in reversible jackets, tents, sleeping bags,and the like, it is desirable to provide the fastener slider with a pulltab on both sides so that the fastener can be opened or closed fromeither side of the item. This has created the need for a new type oflock for the fastener slider since conventional slider locks aregenerally spring biased into a locking position and are designed tocooperate with the pull tab for releasing the slider automatically. Thistype of locking mechanism is not readily adaptable to a double pull-tabslider since the lock must be released by either of the opposed pulltabs in order for the fastener to be effective.

The prior art, as exemplified by U.S. Pat. Nos. 3,226,788 and 3,449,803,is generally cognizant of slider locking mechanisms in which fixedprojections engage the filamentary coupling elements or the stitchingthreads of a slide fastener whenever the fastener carrier tapes arespread apart. U.S. Pat. No. 3,226,788, for example, discloses a slidefastener having coiled filamentary coupling elements which are stitchedonto one side of a pair of carrier tapes such that beads formed by thestitching will be engaged by a pair of identical locking tabs when thetapes are separated. This type of device has the obvious disadvantage ofincreased stitching thread wear. Also, the slider is limited to thoseuses in which coiled filaments are employed and are attached to one sideof the tapes such that a series of protruding stitching thread beads areformed. Likewise, U.S. Pat. No. 3,449,803 discloses a fastener which hasnot proven to be satisfactory under all conditions of operation. In afastener which has a locking projection extending from both flanges oneach side of the slider body, the entry of one of the projections intothe interstices of the filamentary coupling elements on one side of thecarrier tape is often blocked by the abutment of a heel member on theother side of the tape with the other locking projection. This designcoupled with the fact that the filamentary stringers are preferablyconstructed with a low-friction synthetic material, such as nylon, oftencauses the slider to slip open inadvertently. In addition, with a pairof locking projections facing each other on opposite sides of eachcarrier tape, the tendency exists for the filamentary stringers, and inparticular the stitching threads, to become wedged between the lockingtabs as the slider is moved along the fastener chain. Thisdisadvantageous operation is further exaggerated by the fact that thefastener is normally under a force which tends to spread the tapes apartand engage the four locking projections. With four points of engagement,the slider is subject to undue binding that both impedes initial slidermovement and produces rough operation thereafter.

Thus, while numerous attempts have been made in the recent past todevelop an effective flange-lock slider, a simple and improved slider ofthis type for providing positive locking, reduced wear and increasedsmoothness of operation for use in a ladder-type filamentary fastenerhas heretofore been unavailable.

SUMMARY OF THE INVENTION Accordingly, it is an object of the presentinvention to construct a flange-lock slider for a ladder-typefilamentary slide fastener including a main body member having a pair ofspaced, parallel wing members, first and second pairs of opposingflanges extending respec-.

tively from opposite lateral edges of the wing members toward each otherto define a Y-shaped channel for receiving the filamentary stringers,and one flange only of each pair of flanges having a locking tabprojecting therefrom into the channel whereby slider movement along thefastener tapes is facilitated and the locking tabs may be positivelylodged in the space between adjacent heel members of the fastener on oneside of the tape when the slide fastener is spread apart.

Another object of this invention is to construct a flange-lock sliderhaving fewer elements and improved locking and wear characteristics foruse with laddertype fasteners having low-friction synthetic filamentarycoupling elements.

Some of the advantages of the present invention reside in its smoothnessof operation, effectiveness in locking the slider of a ladder-typefastener in place, and ability to provide positive locking actionwithout damaging the slide fastener chain or its stitching threads.

Other objects and advantages of the present invention will becomeapparent from the following description of a preferred embodiment whentaken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary plan view ofaladder-type filamentary slide fastener having a flange-lock slideraccording to the present invention;

FIG. 2 is an enlarged fragmentary side elevational view of the slider ofFIG. 1; and

FIG. 3 is an enlarged sectional view taken along line 3-3 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention isembodied in a ladder-type slide fastener indicated generally at 10 inFIG. 1 including a pair of interengagable continuous filamentarystringers l2 and 112, each having a plurality of generally U-shapedupper heel members 14, 114 and, as shown in FIGS. 2 and 3 a plurality ofgenerally U- shaped lower heel members 16, 116 interconnected by aplurality of head elements 18, 118. The slide fastener 10 additionallyincludes a pair of carrier tapes 20 and 120 upon which the stringers l2and 112, respectively, are attached.

The filamentary stringers are each disposed along a longitudinal edge ofone of the carrier tapes with the upper and lower heel members overlyingopposite sides of the tapes. In this manner, the heel members arealternately disposed on opposite sides of each tape such that theadjacent upper heel members 14, 1 14 are separated by a space insuperposition with one of the lower heel members 16, 116 and vice versa.Filamentary stringers l2 and 112 are held in place by any suitable meanssuch as stitching threads 22 and 122, respectively.

A slider, indicated generally at 24, is disposed on tapes 20 and 120 tofacilitate selective opening and closing of the fastener as is wellknown. Slider 24 has a pair of parallel superposed wing members 26 and28 which are joined at their upper ends (as visualized in FIG. 1) by agenerally rectangular spacing member 30 having its longer dimensionaligned longitudinally of the carrier tapes and 120. Spacing member hasan exterior end 32 which is formed flush with the upper edges of wings26 and 28 and an interior end 34 which is tapered in the plane of tapes20 and 120 to form an apex 36. End 34 of spacing member 30 is alsotapered in a plane normal to the plane of tapes 20 and 120 to form aV-shaped edge 38 as shown in FIG. 2. Edge 38 and apex 36 are joined by asmooth, continuous surface which acts to separate the interengaged headelements 18 and 118 of stringers 12 and 112 as the slider is moveddownwardly along the fastener chain.

Pivotally mounted on the upper and lower surfaces of wings 26 and 28,respectively, are two pull tabs 40 and 42 which facilitate movement ofthe slider 24 along the fastener tapes from either side of the fastener10.

Flanges 44 and 46, forming a first pair of opposing flanges, extend fromone lateral edge of each wing 26 and 28, respectively, toward eachother; similarly, flanges 48 and 50, forming a second pair of opposingflanges, extend from an opposite lateral edge of each wing 26 and 28,respectively, toward each other. Flanges 44, 46, 48 and 50, wings 26 and28 and tapered spacing member 30 cooperate to define a generally Y-shaped channel, as shown in FIG. 3, for receiving the filamentarystringers 12 and 112 of slide fastener 10.

Formed on the upper end of each of diagonally opposed flanges 44 and isa respective one of a pair of locking tabs or projections 52 and 54which extend into the Y-shaped channel. It is important to note that asshown in the drawing, flanges 46 and 48 do not carry any projectingsurfaces and present a smooth surface to the filamentary stringerportions in the channel. The locking projections 52 and 54 have aconstant width which is substantially equal to the width of flanges 44and 50; that is, the tab dimension in the direction normal to the planeof the carrier tapes 20 and 120 is approximately constant throughout itslength and the locking projections do not curve or taper away from thetapes. The locking projections 52 and 54 also have respective innersurface portions 53 and 55 which are relatively square and flat forengaging the filamentary heel members without distorting the same.

In operation, fastener 10 is especially well suited for use inheavy-duty applications or wherever it may be desired to have the slideroperable from both sides of an item. For example, fastener 10 may beinstalled in a tent, reversible jacket or sleeping bag to name but afew. When installed in the desired item, slider 24 will automaticallylock itself in place by the cooperative action of locking tabs 52 and 54and the heel members of the fastener chain. As shown, in FIG.. 3, anyopening or spreading force placed on the fastener 10 causes tapes 20 and120 to spread apart such that the filamentary stringers R2 and 112 aredrawn outwardly until all of the heel members engage the walls offlanges 44, 46, 48 and 50. Since each upper heel member 14, 114 issuperposed over a space between adjacent lower heel members 16, 116 inthe ladder-type chain and in view of the presence of only one lockingprojection for each lateral flange pair, it can be appreciated that thefilamentary stringers are permitted to move to their extreme outermostposition under any spreading force to cause the locking projections tobecome positively locked in the interstices of the fastener elements. Itcan be easily recognized from FIG. 3, that had there been a lockingprojection extending from flange 46 as well as from flange 44, suchprojection would have abutted lower heel member 16 so as to prevent thefilamentary stringer 12 from moving completely out to a satisfactoryposition for establishing the locking engagement of projection 52 withupper heel member 14. As a result, the present construction assurescomplete and positive locking of the slider with both carrier tapes ofthe fastener l0 and, accordingly, is extremely well adapted for use withfasteners having filamentary stringers constructed of a low-frictionmaterial, such as nylon. it is also noted that because of the surfaceconstant width surface portion 53 or 55, respectively, of each of thediagonally opposed locking tabs 52 and 54, abutment of the tabs with theheel portions in the locking position is head-on such that substantiallyall of the locking or movement-resisting forces are directedlongitudinally along the fastener chain. Consequently, the locking tabsdo not tend to distort the heel members of the filamentary stringers outof their normal plane and thus do not produce pinching, abrasion orbinding of the slider during operation as well as upon locking.

When it is desired to open the fastener 10, either pull tab 40 or 42 maybe used and a force applied in a direction to move the sliderdownwardly, as visualized in FIG. 1. Since each pair of opposing lateralflanges 44-46 and 48-50 contains only one locking projection, the numberof locking points or points of filament engagement of slider 24 isminimized, in accordance with the present invention, while stillenabling the locking of both carrier tapes. Since a minimum numberoflocking points exist in slider 24, undue or excessive force need notbe applied to produce initial movement ofthe slider 24 when opening thefastener. Also, the absence of opposing locking projections for eachlateral flange pair minimizes the possibility of filament or stitchingthread binding and wear as the slider is moved thus increasing theuseful life of the fastener as well as the item to which it is attached.

Thus, the present invention provides a slide fastener having improvedlocking characteristics, smoother operation due to a reduction in thenumber of locking points, reduced abrasion and wear, and reduced bindingupon initial movement of the slider to open the fastener. The presentinvention is therefore considered to represent a material advance in theart and has provided a practical and effective solution to a number ofserious problems in this field.

Inasmuch as the present invention is subject to many variations,modifications and changes in detail, it is intended that all mattercontained in the foregoing description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

What is claimed is:

l. A ladder-type filamentary slide fastener comprising a pair of carriertapes each carrying along a longitudinal edge a filamentary stringerhaving a plurality of head elements interconnecting adjacent ones of aplurality of generally U-shaped heel members which are alternatelydisposed on opposite sides of the tape such that adjacent heel memberson the same side of the tape are separated by a space in superpositionwith a heel member on the opposite side of the tape,

a slider having first and second spaced parallel wing members,

a first pair of opposing flanges, each flange of said first pair ofopposing flanges extending respectively from a lateral edge of each ofsaid first and second wing members toward each other on a first side ofsaid slider,

a second pair of opposing flanges, each flange of said second pair ofopposing flanges extending respectively from a lateral edge on each ofsaid first and second wing members toward each other on a second side ofsaid slider,

said first and second pairs of opposing flanges forming a Y-shapedchannel for receiving the filamentary stringers with the heel membersslidingly engaging the respective first and second pairs of flanges oneflange only of each of said first and second pairs of opposing flangeshaving a locking tab projecting therefrom into said channel for beingreceived into a space separating adjacent heel members when a spreadingforce is applied to said tapes, the other flange of each of said firstand second pairs of opposing flanges having a smooth surface allowingfree movement of the respective heel member on the opposite side of thetape from the space receiving said locking tab, each of said lockingtabs having an inner surface portion with a constant width throughoutits length substantially equal to the width of the inner surfaceportions of the respective flanges for engaging said heel memberswithout distorting the filamentary stringers, and one of said lockingtabs extending from a flange on the first wing member and the other ofsaid locking tabs extending from a flange on the second wing member suchthat said locking tabs are disposed in a diagonally opposingrelationship across said channel.

1. A ladder-type filamentary slide fastener comprising a pair of carriertapes each carrying along a longitudinal edge a filamentary stringerhaving a plurality of head elements interconnecting adjacent ones of aplurality of generally Ushaped heel members which are alternatelydisposed on opposite sides of the tape such that adjacent heel memberson the same side of the tape are separated by a space in superpositionwith a heel member on the opposite side of the tape, a slider havingfirst and second spaced parallel wing members, a first pair of opposingflanges, each flange of said first pair of opposing flanges extendingrespectively from a lateral edge of each of said first and second wingmembers toward each other on a first side of said slider, a second pairof opposing flanges, each flange of said second pair of opposing flangesextending respectively from a lateral edge on each of said first andsecond wing members toward each other on a second side of said slider,said first and second pairs of opposing flanges forming a Yshapedchannel for receiving the filamentary stringers with the heel membersslidingly engaging the respective first and second pairs of flanges oneflange only of each of said first and second pairs of opposing flangeshaving a locking tab projecting therefrom into said channel for beingreceived into a space separating adjacent heel members when a spreadingforce is applied to said tapes, the other flange of each of said firstand second pairs of opposing flanges having a smooth surface allowingfree movement of the respective heel member on the opposite side of thetape from the space receiving said locking tab, each of said lockingtabs having an inner surface portion with a constant width throughoutits length substantially equal to the width of the inner surfaceportions of the respective flanges for engaging said heel memberswithout distorting the filamentary stringers, and one of said lockingtabs extending from a flange on the first wing member and The other ofsaid locking tabs extending from a flange on the second wing member suchthat said locking tabs are disposed in a diagonally opposingrelationship across said channel.